BLOOD ON PUTIN'S HANDS: A Russian SA-11 missile launcher, which was used to bring Malaysia Airlines Flight MH17 down, was operated by a Russian crew, according to Ukrainian intellegence officials. Photo: AP

“This terrorist act was committed with the help of the Russian Federation. We know clearly that the crew of this system were Russian citizens,” Vitaly Naida, Ukraine’s chief of counterintelligence, told reporters on Saturday.

The missile system was spirited into rebel-controlled Ukraine territory in pitch-black darkness at about 1 a.m. Thursday, Ukrainian intelligence sources told The Sunday Times of London.

The Buk missile system crossed the Russian border near the village of Sukhodolsk. By 9 a.m., it reached the city of Donetsk, a rebel stronghold and command center.

Accompanied by an escort of T-72 tanks, the launcher left Donetsk, headed east. At a news conference, Naida showed reporters what he said were photos of the Buk launcher being transported through the region.

One Ukrainian photo shows the missile launcher next to a supermarket in a town square.

Ukrainian intelligence recorded phone calls between a Russian military intelligence officer, Sergei Nikolaevich Petrovskiy, and a rebel fighter.

“Where should we unload this cutie?” the rebel fighter asked.

“Is it what I’m thinking about?” replied Petrovskiy.

“Yes. Buk, Buk,” said the fighter.

Crews brought the system to a spot near the village of Pervomaysk, about 75 miles from Donetsk.

Ukrainian government forces maneuver a SA-11 launcher as they are transported northwest from Slovyansk, eastern Ukraine on July 4.Photo: AP

It was parked there at about 4:10 p.m. Thursday when a Russian operator reported to a rebel officer known by the nom de guerre “Miner” that the system had picked up a high-altitude aircraft.

Miner allegedly gave the fateful order to fire, The Sunday Times said.

Ukraine’s intelligence service posted on its Web site a picture of what it says is the contrail of the killer missile.

At first, the rebels were jubilant about their hit.

“We have just shot down a plane,” a rebel field commander said in a phone call to a Russian military officer that was recorded by Ukrainian intelligence.

Soon after that, Igor Girkin, the leader of the Donetsk People’ Army, boasted on a Russian social media Web site that his soldiers had shot down a Ukrainian plane.

“We did warn you — do not fly in our sky,” Girkin crowed.

We have found the first 200 [dead]… We are 100 percent sure that it was a civilian plane. - Rebel report to his superiors after searching MH17's debris

But the rebels soon realized their mistake. “We have found the first 200 [dead],” a rebel reported to one of his superiors. He added: “We are 100 percent sure that it was a civilian plane.”

Girkin’s boast was soon pulled from the Internet.

Sometime after 11 p.m. that night — seven hours after the Boeing 777’s debris and its 298 passengers rained down on Ukrainian homes and fields — the rebels began moving the missile system back toward the Russian border.

Ukrainian intelligence says Russia pulled back two missile launchers — including the one used against Flight 17 — “to suppress evidence of its involvement in the terrorist act.”

Ukrainian officials say their account is based on intercepted cell phone calls and satellite images.

The Buk missile system, introduced 35 years ago, is a mainstay of the former Soviet surface-to-air arsenal, The Sunday Times of London said.

Russia is believed to have about 350 Buk missiles. They are capable of hitting targets at an altitude 72,000 feet. That’s far above the 33,000 foot altitude at which the Malaysian jet flew.

The Buk system can identify “friendly” military aircraft, but can not pick up the airliners’ transponder signals, an expert with the defense publication IHS Jane’s told the newspaper.